SWELL ALERT: Nazare To Go Nuclear Tomorrow?

Another big west swell is ripping across the North Atlantic. This time, it will be Portugal’s turn to get the biggest, cleanest surf.

This low is sitting about 1,000-miles west of Biscay, with a strong westerly fetch on its southern flank. It has been moving slowly east for the past 48 hours, the fetch persisting and chasing the large westerly swell it is generating.

Could we see an out of season super session throw down?

The system is just about to swing northeast, and is expected west of Scotland by midday Tuesday. The fetch ends up over Ireland, so northern areas will experience ragged conditions, but a ridge of high pressure pushes up from the south making southern areas much cleaner.

A large, long-period swell begins to hit west-facing spots tomorrow (Tuesday April 17) and then gradually decreases over the following days. It will be biggest in Ireland, but most of the time severely hampered by strong to gale-force southwest winds. However, these could back south-southeast for a while on Wednesday.

In Portugal, things are much better. Wave heights increase during tomorrow, exceeding 15-feet at exposed spots, and then gradually decreasing. The long period means enhanced focusing at places like Nazaré, which will be much bigger than surrounding spots. Expect light offshores in the morning, but onshore breezes from midday onwards.

That system coming in this evening...

The other good option is southwest France. Tuesday could see some medium-sized combo swell before the big one arrives later on. This could be off the scale for the beachbreaks, particularly north of Hossegor; but the big-wave spots could be good, perhaps hitting 15-feet for a while. The swell drops steadily, persisting through Thursday and Friday. Conditions are excellent throughout, with light winds from an easterly quarter.

Note that his week’s forecast is a good example of a stable situation, the low sticking to its trajectory and that ridge becoming a reliable feature. At spots in the south you can see the MSW probability parameter already showing close to 100 per cent for most of the week.